Chon-ji: Drills and Variations
The variation we did was using the lower block to defend against a grab and punch. The attacker or opponent grabs wrist/elbow/shoulder and then performs a roundhouse punch with the other hand. The fold for the lower block defends against the oncoming punch - irrespective of the hold, and then the lower block or hardan marki is used as a groin strike.
This is a nice oyo or variation in that it takes the theme of 'folding' to block a separate technique, and then uses the block as a strike at the end of the technique. What I also like about this application is that it requires the user to 1) change the position of the fold to meet the oncoming strike, and 2) to rotate the body core in order to slip past the truncated oncoming roundhouse strike in order to strike the groin. So while a 'typical' lower block will be done on the line, this application would require the body to be rotated away from the blocking hand. All in all a very healthy exercise in order to show the white belt that you need to modify theoretical techniques in order to place the strike onto the opponent's body.